The invention relates to a bearing for spindles of spinning or twisting machines having a spindle bearing housing which contains a collar bearing and a step bearing with a pivot bearing for a spindle shaft which is equipped with a driving wharve reaching over the collar bearing.
A bearing of the initially mentioned type is the object of the above-noted parent application Ser. No. 365,716, which in turn is based on German patent application No. P 38 20 327.8. This bearing is designed particularly for smaller spindles in order to produce the currently required cop lengths of from 180 mm to 250 mm in the case of a ring diameter of maximally approximately 50 mm. It is necessary that such spindles operate perfectly between 3,000 min.sup.-1 and 25,000 min.sup.-1. Because of the design according to the older application, it is possible to provide the spindle shaft in the area of the collar bearing with a diameter which amounts to no more than 7 mm. In connection with the collar bearing provided in the older application which is constructed as a roller bearing, it is possible to reduce the outside diameter of the driving wharve to 19 mm. By means of this bearing, the power requirement may be reduced.
An object of the invention to construct a bearing of the initially mentioned type in such a manner that the power requirement may be further reduced.
This object is achieved by means of the fact that the distance between the collar bearing and the pivot bearing is no more than 100 mm and the diameter of the spindle shaft in the area of the collar bearing is no more than 7 mm, that the collar bearing is a needle bearing, and that the driving wharve has an outside diameter of no more than 17 mm.
By means of the construction according to the invention, it is possible to reduce the outside diameter of the driving wharve by at least 2 mm so that, as a result, the speed of a driving belt can be reduced which is required for the high rotational speeds. The driving power required during the no-load running of the spindles may be approximately 11% to 12% lower. Relative to the spinning output, the energy savings therefore amount to approximately 2%. In view of the high energy costs, this is a considerable advantage.
As a further development of preferred embodiments of the invention, it is provided that the receiving device of the needle bearing contains an outer ring with a flanged disk which is joined in one piece. This permits very precise bearing characteristics. In order to permit swinging motions of the spindle shaft, it is provided in a further development of the invention that the outer ring of the needle bearing is provided with a running surface for the needles which is arched in axial sectional view. As a result it is possible that the spindle shaft can carry out swinging motions in the area of the step bearing which can be absorbed without any tilting by the needles in the area of the collar bearing.
In a further development of preferred embodiments of the invention, it is provided that the collar bearing is held in a head bearing sleeve which, in proximity of the collar bearing, is connected with a centering tube whose end inserted into the head bearing sleeve is widened by means of plastic deformation before it is inserted. A centering sleeve which is widened or "flared" in this manner, can be fastened securely in the head bearing sleeve without the occurrence of excessive forces in axial direction during the mounting. For the same purpose, it is advantageous for the head bearing sleeve, in a further development, to have an interior surface, which tapers in the direction of the step bearing, in the section in which the head bearing sleeve is connected with the centering sleeve. In the case of the larger spindles which correspondingly have larger dimensions, no limitations were known of forces occurring during the mounting.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.